1. Field of the Invention
This disclosure is related to electronic devices.
2. Description of the Related Art
A multi-context reconfigurable device in which a configuration can be instantaneously switched is suggested (e.g., Non-Patent Document 1). For example, Patent Documents 1 to 5 each propose a field-programmable gate array (FPGA) that includes a transistor containing an oxide semiconductor in a channel formation region (hereinafter referred to as OS transistor) and functions as a multi-context reconfigurable circuit.
Patent Documents 1 to 5 each disclose that the use of a memory including an OS transistor as a configuration memory for storing configuration data enables configuration memories to be arranged at a high density, resulting in high degree of integration of configuration memories. This fact is suitable for a multi-context system.
Since unused configuration data are held in a set of configuration memories in a multi-context system, an OS memory consuming low power in data retention is preferable. Moreover, the boosting effect sometimes increases the switching speed of a routing switch.